Well, in the sense that it removes the need for a cancer-leaking CRT monitor or TV. The EON Super 64, as it's creatively titled, is a plug and play solution to connecting your N64 to your modern telly or monitor and doesn't require a power-source, while also upscaling games to a whopping 480p.
Which isn't to be mocked at, especially given non-Expansion Pak'd games presented at a native 320x240. And having a HDMI parse through just removes clutter and mucking around if, you know, you're not into the ROM scene, which we don't condone AT ALL *surreptitious wink*.
EON, the creators of the acclaimed GCHD and GCHD Mk-II, upscales N64 classics by delivering gorgeous 480p — double the N64’s native resolution — and truly lagless input with the EON Super 64. The optional “Slick Mode” even smooths jagged edges, making classics look sharper than ever. EON delivers the first device that respects the original hardware without risky modifications and external power sources.It should be noted that this device currently only works with NTSC consoles (ie US and Japan because the past). Watch a 'video' highlighting the EON Super 64 embedded below.
Can't speak for the Super64 but the Gamecube GCHD adapter worked on my Aus gamecube. I ended up getting my N64 modded about a year ago with the UltraHDMI mod but it is a more expensive option.